My dad and I had been discussing the review I’d written about Dr. Anthony Martin’s latest book, “The Evolution Underground.” He voiced this confusion with more concern for the overall safety (and perhaps sanity?) of the Emory professor and his students than an interest in what knowledge they hoped to gain.

To be fair, my dad hadn’t yet read this or any book about ichnology and was not familiar with the field. My inability to make that part of the book clearer aside, it also spoke to a question I’d had this past December. Speaking with him by phone, I asked Dr. Martin: Did he think more people know about ichnology as a result of his prolific work?

“I think,” he began thoughtfully, “through the books, [through] giving public talks, and [by blogging] about it, I’m fairly confident in saying, ‘yes, more people are more aware now of ichnology as a science.’ I think that ‘Dinosaurs Without Bones’ was a really good step [toward] popularizing ichnology as science, and then I think that ‘The Evolution Underground’ will take it another step further.”

Image of Dr. Anthony Martin, courtesy of Emory University

It is telling that, of the four books Dr. Martin has written so far, three of them focus on ichnology. His handle on Twitter is @ichnologist. Most of his blog posts feature concepts related to ichnology. During our conversation, he chuckled and admitted he refers to himself as an “ichno-evangelist.”

Any physical remnant of an extinct or extant creature falls into ichnology: bites, scratches, footprints, marks indicating the drag of a tail, coprolites or scat. Reading those traces—recognizing them for what they are—is a skill, and one for which there are relatively fewer reference points than the much older field of paleontology.* Dr. Martin explains this in his first work with Pegasus Books, “Dinosaurs Without Bones.” It is one thing to see a fossil femur, for example, and understand what it is. Recognizing a fossil nest, however, or a fossil burrow, is considerably more challenging. Without “search images” or reference points that help other scientists understand what to look for, such fossils might be easily missed.

Detail of a slab of fossil footprints surrounded with what are believed to be fossil raindrops at the Beneski Museum at Amherst College, Massachusetts. Both the footprints and the raindrops are examples of ichnology. Picture taken by the author of this blog.

Can you tell what these are? I can’t, and, so far, neither can the experts. As-yet unknown trace fossils at the Beneski Museum at Amherst College, Massachusetts; pictures taken by the author of this blog.

Figure 1: A brief summary of animal burrowing through time, from the Ediacaran Period through today. Geologic eras on left, periods on right, MYA = millions of years ago, and red arrows indicate times of mass extinctions in the geologic past. (Image and caption used with permission from Pegasus Books)

“Sage scents wafted by on the wind and, in between scoops, I looked around at the nearby pine forests and rolling, high-plains grassland nearly everywhere else, then up at an expansive blue sky hosting white, fluffy clouds. You might say I was in a country where the sky was big: Some people just call it ‘Montana.’” – page 87, “The Evolution Underground: Burrows, Bunkers, and the Marvelous Subterranean World Beneath Our Feet,” by Dr. Anthony J. Martin, Pegasus Books

In the book, Dr. Martin describes participating in an excavation in the Blackleaf Formation that lead to the discovery of the first known fossilized burrow, found collectively by Dr. Martin, Yoshi Katsura, and Dr. David Varricchio of Montana State University.

This discovery—based solely on noticing the odd structure of sediment surrounding bones—is no small feat. Looking at an image of this burrow, which you can see in Dr. Martin’s blog post here, I am amazed that anyone would be able to decipher what it actually is when working through layers of other rock, let alone when it was completely revealed.

Dr. Martin credits his mentor and former professor, Bob Frey, with guiding him in ichnology. Both Dr. Varricchio and Dr. Martin were fellow students in his class, a class that seems to have been a road map for both of them in their future discoveries.

And while in this book Dr. Martin discusses many extant burrowers, he certainly addresses those found in the fossil record as well.

Figure 38: Early Cretaceous (130 mya) lobster burrow preserved as natural cast on bottom of limestone bed, Portugal. Although the lobster’s body is not preserved, its leg impressions and body outline were left behind. (Photo by Anthony J. Martin; image and caption used with permission from Pegasus Books)

“The bigger picture behind these everyday observations of many holes in the ground, however, is that the long history of these burrowing invertebrates completely altered global environments, from the deepest sea to the highest mountains, and even affected the atmosphere and climate. In short, the entire surface of our planet is built upon one big complex and constantly evolving burrow system, controlling the nature of our existence.” — page 14, “The Evolution Underground: Burrows, Bunkers, and the Marvelous Subterranean World Beneath Our Feet,” by Dr. Anthony J. Martin, Pegasus Books

The quote above is the central theme of “The Evolution Underground.” I wondered if he’d gained this perspective after completing the book, or if this was something he carried as he began writing.

“I did go in with that big picture idea about burrows having this overarching influence on all of our ecosystems,” he replied. “[That, we, too,] have this evolutionary heritage that [is] connected to burrows. So I did have that idea in mind, but it was really scattered. Really disparate. Also, it wasn’t an original idea. Lots of other people really deserve credit for that, [and they are] cited in the endnotes of the book.

But, he said, “[w]riting the book definitely helped me pull together a lot of those previously separated ideas into the theme that I summarized as ‘burrows acting as the midwife in the birth of Gaia.’

“We can’t really talk about the evolution of ecosystems or the evolution of life without talking about burrows.”

Figure 16: Folk-art rendering inspired by the Lystrosaurus saga set during the Permian-Triassic transition (Chapter 5), with a cutaway view of a Lystrosaurus burrow. (Artwork by Ruth Schowalter and Anthony J. Martin; image and caption used with permission from Pegasus Books) — (The author of this blog wants to note, as Dr. Martin does in the endnotes, that his interest in the species was inspired by this piece by Annalee Newitz.)

Having written four books, did writing them get easier?

“It did get easier with each book,” he acknowledged. Then laughed. “But, of course, the word ‘easy’ is relative.”

“[‘The Life Traces of the Georgia Coast‘] was hard to write because it was so comprehensive. It was almost 700 pages long; it had more than 800 peer-reviewed references. It’s an academic book, but I [also] wrote it for a popular audience. So it’s a hybrid kind of book in that respect. That took four years from the acceptance of the book proposal to actually holding it in my hands.”

“And,” he added, “a book is not finished until I’m holding it in my hands.”

“In contrast to that, ‘Dinosaurs Without Bones’ was quick. That took me—from start to end—less than two years. I felt like [‘The Evolution Underground’] was a little bit easier than ‘Dinosaurs Without Bones,’ but that’s only because I used Pegasus Books again as the publisher. And I had the same editor: Jessica Case. With that said, it was still difficult to write because it covered so many different burrowing animals, [not to mention it covered] the last 560 million years!

“The main takeaway point of it is for people to better appreciate the world they don’t often see, and that’s the world below their feet. We might not even be here talking about burrowing animals if our earliest mammalian ancestors hadn’t burrowed.”

*This comment is not meant to hold one field over another. I have great respect for the skills needed for both paleontology and ichnology.

******

Thank you to Carol Clark, Senior Science Communicator at Emory University, for the wonderful picture of Dr. Martin!

A sincere and enthusiastic THANK YOU to Dr. Anthony Martin for his willingness to connect by phone and for his generous responses to my questions! It was a pleasure and an honor to be able to speak with him, and—like his writing—he made it fun! I eagerly (if impatiently) await any possible future work.

FULL DISCLOSURE: The author of this blog loved Dr. Martin’s previous book with Pegasus, “Dinosaurs Without Bones,” and thus, jumped at the chance to review his latest work (fully predisposed to embrace it) by requesting a review copy from the publisher. I am very grateful to Pegasus Books for the opportunity to do so. Being able to use such beautiful images from the book is a great honor! I am specifically grateful to Deputy Publisher, Jessica Case, with whom it was wonderful to work!!